The present invention relates to controllers for irrigation systems, in general, and, more particularly, to irrigation system controllers employing solid state logic and control circuitry.
Reference is made to U.S. Pat. No. 4,165,532. entitled "Automatic Irrigation Sprinkler System Controller" by T. L. Kendall, et al. and to U.S. Pat. No. 4,189,776, entitled "Simplified Irrigation Controller, by T. L. Kendall, both of which patents are assigned to the common assignee of this application. In each of these patents there is described a solid state controller for the operation of irrigation systems. The solid state controller described in U.S. Pat. No. 4,165,532 is particularly adapted for large commercial irrigation systems such as those employed in parks, golf courses, and the like. Accordingly, the input keyboard and the logic sequences incorporated therein are adapted to provide the operator with a wide selection of features. Start times, run times, and the like are directly input as alpha-numeric data through the keyboard which incorporates a plurality of keys for the input of such data.
The advantages attendant to such automated programmable solid state controllers are of equal benefit to the typical homeowner. The time normally devoted to the diligent watering of lawn and plant areas can be a major consideration to a homeowner. This is particularly true when the homeowner wishes to be gone for extended periods of time wherein arrangements must be made, with attendant cost, for someone to come in to perform the watering chores normally accomplished by the homeowner. While the benefits of an automatic controller for the home irrigation system are apparent, these benefits usually do not justify the expense of a complicatad professional controller such as described in the patent noted above.
In U.S. Pat. No. 4,189,776, there is described a simplified solid state irrigation controller particularly adapted for low cost availability to the non-professional user. This patent describes a simple step-by-step method for changing the start times, runtimes and active days for individual watering stations within the controller. Once this information has been selected and placed within the memory of the controller, however, the controller is not flexible enough to permit an individual watering station to be turned on for a single selected day within a fourteen-day cycle, for example.